Its 1" between top and horn at the front baffle and 1 1/4" (1 15/64") between top and horn at the rear just before it angles downward. So its only 1/4" of taper over a 10 3/4" span. That's how I read the plans anyway, am I wrong?

You have the taper correct, and yes Donnie that is a 1-1/4 degree angle.

If you look at the plans, (if I have the same set of plans you get when purchasing the plans) you will see that the dimension is from the top of the side panel of the cabinet to the underside or bottom of the first piece. So you should have a 1" gap in your pair, which is what grabbed my attention The gap should only be 1/2" not 1" Funny thing, I did the exact same thing on Steve's pair and have been building them that way ever since. To remedy the problem add another 1/2" piece, attached to the top of the piece you have already in place. I did this but instead of the 2" port hole I used a 5" whole, so it wouldn't be adding length to the 2" port.

However in this case, it also looks like at the first bend where you have added the 45 degree wedge. it is also larger than the 3/4" you need. Again that could be a illusion from the photo....

I got my air gap fixed, at least on the first part of the horn. Had to cut a 2" strip out of the top of one side to open it up, glue in the spacer piece, and then seal it back up. All the while I was asking myself "why am I doing this? This isn't going to make any difference!" But it did! The darn things sound pretty good now. Before they sounded like a cheep transistor radio (in stereo - twice as bad!! ). Then I added a $10 bullet tweeter I had lying around and that made a huge difference also. These guys are worth listening to now!

Aura driver at $3.60 from Madisound and a $8.99 bullet tweeter from Electronix (p/n 11-110). Plus a 8 uf cap for the tweeter and a 4 ohm resistor because the tweeter is a little too loud. So, less than $15 per side for the speakers and crossover.

I just got the plans for these and would really like to keep this thread going....I think I'll try the cheap Auraosound's also and add a floating tweeter on top (maybe a tractix). Someone mentioned a ribbon tweeter. Any suggestions on tweeters from Madisound that wouldn't break the bank. (I am a total newbie to crossovers).

Ribbon tweeters are fast, and that's why I prefer their sound. It seems to me to be a good marriage with a horn design. If you might be interested, I have a set of ribbons that I might let go of. They basically have only a few hours on them. Anyway, keep me up to date here about your progress, as I plan to build this horn as well in the future.

Here is an earlier post I moved over from another thread to keep things together on this subject of replacement DNA drivers. Zygi has come up with an alternative (but more costly) set of drivers.

I have the W5 driver, but was looking for something that would play a little louder with my amp while preserving the imaging, bass and detail of the W5. I believe Zygi's configuration does all this plus some.

Here are the instructions I worked from:

The drivers are SB acoustics...sb15nrxc30-4 Vifa...xt25sc90 Coils are 0.1 16 gauge sidewinder Caps are 4.7 I would start with the PX4.7 Clarity Cap (Personally I like, for a cheap cap, the Jenzens from Parts Express there next up from the cheapest. If you like what you hear and they work, I would then proceed to the Mundorf Supreme, not worth while unless you like the system as a whole.

Note: Cap is on the tweeter, coil on the woofer. The tweeter is wired out of phase. Hole for the W5 is 122mm and the hole for the SB is 123mm (or vice versa) so it will fit if you have already made the hole in your baffle. I had to re-drill the mounting holes because I couldn't get the new driver to line up with the W5 holes.

Go to your local Home Depot/ Lowes and buy some fiber board (Cylotex) like they use for house wrap. It's black on one side and natural on the other side. This was what I used, from the outside to cut my inclosed volume down to almost half.

Note: I cut two peices of material slightly wider than the chamber width and put them in through the existing hole, then wedged them against each side to form an upside down V and pushed them down into place. Then I taped the seams. You want the new floor of the chamber to be just below the driver.

For the tweeter hole, Bob suggested 1/2" distance between the flange of the tweeter and the flange of the woofer.

Just as a followup, I updated the cap to a Mudorf 4.7 tin foil (ZN) cap with good results. Originally Zygi had recommended the Supreme, but later suggested the ZN because he finds it a little more clarity.

I think you'd be ok with the height but the width of the driver might be tight. Not sure of the sound. Steve has tried quite a few drivers so I'd look to his recommendation unless you already have the tang bands.

If you don't mind altering the plan for a tweeter the aura drivers Steve recommends are actually pretty good drivers. I just used 4 of them in another project and for $3.60 I don't think you can beat them.

The combo I describe above sounds excellent and I have messed with that for over 4 months. You might pm zygi to see the latest crossover. He has been experimenting.

Here is some more information on drivers for the DNA. I cut a slightly bigger hole and tried some 6.5" speakers:

1) I found in my 2-way DNA with the inexpensive 5" AuraSound driver and a bullet tweeter that a 0.33 mh coil before the woofer (about 4000 hz) made the system sound a lot better. I don't know why or understand this. I normally run the woofer full range, but in this case it looks like the woofer is happier not doing this.

2) I tried the 6.5" Audio Nirvana, Super 6.5, with the worlds worst results. I like this driver in other cabinets but it does not work in the DNA.

3) I tried the Dayton 6.5" full range, Parts Express PS180-8, duplicating the worlds worst results. I like this driver in other cabinets but it does not work in the DNA.

5) I found a used pair of Fostex FF-165k on Ebay (my first Fostex ever), and they sound pretty darn good. They can run with or without the coil so I'm running them full range. They seem to benefit when the tweeter is added in, but that's probably just my 60 year old ears.